CBSE Class 9 Science Improvement in food resources Notes

CBSE Class 9 Science Improvement in food resources Notes. There are many more useful educational material which the students can download in pdf format and use them for studies. Study material like concept maps, important and sure shot question banks, quick to learn flash cards, flow charts, mind maps, teacher notes, important formulas, past examinations question bank, important concepts taught by teachers. Students can download these useful educational material free and use them to get better marks in examinations.  Also refer to other worksheets for the same chapter and other subjects too. Use them for better understanding of the subjects.

IMPRONEMENT IN FOOD RESOURCES 

INTRODUCTION

There is a need to introduce production efficiency of crops and livestock because

1. rapid increase in population

2. No major scope of increasing area of land under cultivation.

Increase in food production without degrading our environment and disturbing the ecological balance i.e. Sustainable Practices are required in agriculture and animal husbandry.

TYPES OF CROPS

Cereals: wheat, rice, maize, millets and sorghum. Provide carbohydrates for energy requirements.

Pulses: pea, gram, black gram, green gram, pigeon pea and lentil. Provide proteins

Oilseeds: soya bean, ground nut, sesame, castor, mustard, linseed and sun flower. Provide necessary fats. Vegetables, spices and fruits provide vitamins and minerals.

Crop means plants of same origin grown together in bulk. Every crop requires different climatic condition, while some crops grow together on one season. The climatic condition, warmth, photo-period for growth and completion is required for different crops.

Two seasonal change types :

a) Kharif crops

b) Rabi crops.

Main seasonal plants are divided into two broad categories. The crops that grow in monsoon period is called Kharif crops which is around June to October. The crops that are harvested in winter period are called Rabi crops which are around November to April.

RABI CROPS 

Rabi crops or Rabi harvests are the crops in agriculture that are sown in winter or cold season. They are harvested in the spring. Rabi is Arabic word which in actual means “spring”. Thus the word “Rabi” is used frequently in subcontinent. Rabi is grown around the month of November to April in our subcontinent. The water collected from the rain in this season is the main source of water in these plants. Rabi crops require greater amount of irrigation. Thus heavy raining may ruin a Kharif crop but it is healthy and beneficial for Rabi crops. These

crops are then taken out at departure of the monsoon rains. The harvesting may begin by April or may. Major Rabi crops that are harvested in subcontinents are wheat, grams, peas, mustard, linseed and barley. Most of the crops are under Rabi season. It is an integral crop in our area.

KHARIF CROPS

Kharif crop refers to the farming, plowing, reaping and harvesting of any household plant sown in the rainy season. It is derived from mochas words in subcontinent. In subcontinent they are popularly known as monsoon plants. They are cultivated for autumn harvest. By the beginning of first rain in July during south west rainy season in monsoon the crops are sown. Its begins at April 16 to October 15 in Pakistan, while in India Kharif season varies state to state in may and ending latest by January. Popularly in subcontinent it starts in June and ends by October. The Indian subcontinent is referred to areas covering India, Pakistan, Nepal and Srilanka. These crops are totally dependent on quantity of rain and water as well as its timings. Too much or too less will affect its growth and the whole effort can go wasted. The harvesting period coincides with the beginning of winter/ autumn in Indian subcontinent it is called Kharif period or Kharif crops. The major Kharif crops that are harvested in sub continent are paddy, soyabean, maize, pigeon-pea, and cotton, green and black grams.

DIFFERENCE BETWEEN KHARIF AND RABI CROPS

♦ Kharif crops sown between April and May while Rabi crops are sown between September and October.
♦ Kharif crops are harvested after monsoon rains while Rabi crops are produced after winter.
♦ Kharif crops are popularly known as monsoon crops while Rabi crops are called winter or spring crops.
♦ Kharif crops are completely relying over the rain like if less or more in quantity while Rabi can deal with whatever water is present for irrigation. Rain has less impact over Rabi crops.
♦ The major examples that can be counted as Kharif crops are sunflower, rice, sugar cane, soya bean and tea while Rabi crops can be wheat, barley, pea, gram and mustard.

Q1. What do we get from cereals, pulses, fruits and vegetables?

Answer:
(i) Cereals provide us with carbohydrates. Also, they are a rich source of energy.
(ii) Pulses give us proteins.
(iii) Fruits and vegetables are a rich source of vitamins and minerals. A small amount of proteins, carbohydrates, and fats are also present in them.

IMPROVING CROP YIELD

The practices involved in farming are divided into three stages. They are
(a) Choice of seeds for planting
(b) Nurturing of the crop plants
(c) Protection of the growing and harvested crops from loss.

Hence the major activities for improving crop yields can be classified as
(i) Crop variety improvement
(ii) Crop production improvement
(iii) Crop protection improvement

CROP VARIETY IMPROVEMENT

This approach depends on finding a crop that can give a good yield. Some of the factors for which variety improvement is done are:
♦ Higher yield: for increasing the productivity per acre.
♦ Improved quality: quality considerations vary from crop to crop as per the requirements.
♦ Biotic and abiotic resistance: crops should have sufficient resistance to biotic factors (diseases, insects and nematodes) and abiotic stresses (heat, cold, frost etc.)
♦ Change in maturity duration: the shorter the duration, the more economical is the variety.
♦ Wider adaptability: it can be grown in different climatic conditions.
♦ Desirable agronomic characteristics: tallness and profuse branching for fodder crops. Dwarfness is desired for cereals.

This can be achieved by two methods; hybridisation and genetically modified crops.

1. Hybridisation
In genetics, hybridisation is the process of combining different varieties or species of organisms which are genetically dissimilar to create a hybrid. It can be inter varietal, inter
specific, intergeneric.

2. Genetically modified crops
Here the crop is improved by introducing a gene that would provide desired characteristics.

Q1. How do biotic and abiotic factors affect crop production?

Answer:

A variety of biotic factors such as pests, nematodes, diseases, etc. can reduce the net crop production. A pest causes damage to agriculture by feeding on crops. For example, boll weevil is a pest on cotton. It attacks the cotton crop, thereby reducing its yield. Weeds also reduce crop productivity by competing with the main crop for nutrients, light, and space.

Similarly, abiotic factors such as salinity, temperature, etc. affect the net crop production. Some natural calamities such as droughts and floods are unpredictable. Their occurrence has a great impact on crops sometimes, destroying the entire crop.

Q2. What are the desirable agronomic characteristics for crop improvements?

Answer:

The desirable agronomic characteristics for crop improvements are:
(i) Tallness and profuse branching in any fodder crop.
(ii) Dwarfness in cereals.
These desirable agronomic characteristics help in increasing crop productivity.

CROP PRODUCTION MANAGEMENT

It involves different practices carried out by farmer to achieve higher standards of crop production. It includes the following:
1. NUTRIENT MANAGEMENT
2. IRRIGATION
3. CROPPING PATTERN

NUTRIENT MANAGEMENT

The higher yields of crops mainly depend upon input applications like improved seeds, fertilizers and modern techniques of sowing and harvesting. Plants require a number of
nutrients for their growth and development.
Plants get nutrients from air, water and soil. Nearly 16 elements are essential for plant growth and reproduction.
On the basis of the requirement by the plants, they are further classified into Macro Nutrients and Micro Nutrients.

MACRO NUTRIENTS

Elements which are needed in large quantities for growth of the plants are called Macro Nutrients. They are Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous, Sulphur, Potassium,
Calcium, Magnesium and Iron.

MICRO NUTRIENTS

Elements which are needed by the plants in very small quantities are called Micro Nutrients. They are Manganese, Copper, Molybdenum, Zinc, Boron and Chlorine.
Deficiency of these nutrients affects physiological processes in plants including reproduction, growth and susceptibility to diseases. To increase the yield, the soil can be enriched by
supplying these nutrients in the form of manure and fertilizers.

Q1. What are macro-nutrients and why are they called macronutrients?

Answer:

Macro-nutrientsare nutrients required in relatively large quantities for growth and development of plants. They are six in number. Since they are required in large quantities, they are known as macro-nutrient. The six macro-nutrients required by plants are nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur.

Q2. How do plants get nutrients?

Answer:

Plants require sixteen essential nutrients from nature for their growth and development. All these nutrients are obtained from air, water, and soil. Soil is the major source of nutrients.
Thirteen of these nutrients are available from soil. The remaining three nutrients (carbon, oxygen, and hydrogen) are obtained from air and water.

MANURE

Manure is an organic substance and is prepared by the decomposition of plant and animal wastes.

Advantages of Manure

♦ Manures helps in enriching the soil with organic matter and nutrients.
♦ It helps in increasing the soil fertility.
♦ Water holding capacity of soil is increased.
♦ Helps in improving soil texture.
♦ Save our environment from excessive use of fertilizers. Manure is classified into two types according to the biological material used:

COMPOST AND VERMI-COMPOST

Composting: It is the process in which farm waste material (cow dung, domestic waste, sewage waste etc) is decomposed in pits. Compost is the aerobically decomposed remnants of
organic matter which is rich in nutrients.

Vermicomposting: It is the process which involve use of earthworms to hasten the process of decomposition of plant and animal refuse.

GREEN MANURE
Leguminous plants like Sunn-hemp or Cluster Bean are grown and then mulched by ploughing them back into the soil. This helps in enriching the soil with Nitrogen and Phosphorous.

FERTILIZERS
Fertilizers are chemicals commercially produced in factories and used as plant nutrients. They supply Nitrogen, Phosphorous, Potassium, etc., They are used to ensure good vegetative growth giving rise to healthy plants.

Please click the link below to download CBSE Class 9 Science Improvement in food resources Notes.